Rock drill



06f.' 25, 1932T E, G, GAR-NN 1,884,652

' ROCK DRILL Filed July l0, 1929 Patented Oct. 25, 1932 UNITED STATES PATEN'llA OFFICE ELMER G. GARTIN, F CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN l i MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS `ROCK DRILL Application ledfJuly 10, 1929. Serial No. 377,273.

This invention relates to rock drills and more particularly to improved pressure fluid operated impact motors for such drills.`

`An object of this invention is to provide 'L5 an improved pressure fluid motor of the imy ing a lubricant reservoir formed inV the rear motor head. These and other objects of this invention will, however, subsequently more fully appear.

In the accompanying drawing there is shown for purposes of illustration one embodiment which the invention may assume in practice.

In this drawing,- i Fig. 1 is a central longitudinal sectional View illustrating' a pressure fluid motor having embodied therein the improved distributing valve structure and themotor lubricating means.

Fig. 2 is a transverse vertical sectional view taken substantially on line 2-2 of Fig. 1.

In this illustrative construction there is shown a pressure fluid motor of the impact type comprising a cylinder 1 having a bore 2 in which a hammer piston 3 is reciprocably mounted. As is usual in rock drilling motors of the type disclosed, the hammer piston is provided with a forwardly projecting striking bar 4 which is adapted to Vdeliver repeated blows on the shank of a usual drill steel (not shown) suitably supported at the forward end of the motor cylinder. This striking bar 4 moves in a bore 5 formed in a front motor head or buer ring 6 suitably carried within the forward end of the cylinder. Fitting the rear end of the cylinderbore 2 is a rear motor head 7 held against rotation by a pin and slot connection 8 and'having an enlarged flanged portion 9 clamped be tween the rear end of the cylinder and a rear head block 10. The front motor head 6, the cylinder 1, and rear head block 10 are held in assembled relation by usual side bolts shown at 11 and 12 in Fig. 2. A usual ratchet 4 and pawl mechanism, generally designated 13, is employed for effecting intermittent r0- tationA of the hammer piston during its reciprocation to thereby effect rotation of the drill steel, and herein includes a rifle bar 14 extending through a central bore 15 formed ci within the head 7 and having spiral grooves 16 interlocked with spiral lugs 17 on a rifle nut 18 threadedly connected within the piston head. This intermittent rotation mechanism includes a usual ratchet ring 19 thrcadedly connected within the `head block 10, and this ratchet ring engages the flange on the head 7 to maintain the latter in position. As

shown, the rearv end of the rifle bar 14 is journaled within a bore 20 formed within a ring-like member 19 suitably positioned within the head block 10. A usual cleansing fluid supply connection 21 is provided and includes a tube 22 extending forwardly centrally through the rifle bar 14 and the striking bar 4 and into position to convey cleans ing fluid to the drill steel in a well known manner. As the specific construction of the intermittent rotation mechanism 13 and the i l cleansing fluid supply connections 21 does not enter per se into this invention, further description of the same is thought unnecessary. Y

Now referring more particularly to the improved fluid distributing valve structure, it will be noted that formed in the lateral projection or boss 23 integral with the motor cylinder is a bore 24, herein preferably ar ranged parallel with the cylinder bore and 31 at its forward end .abutting against the rear end surface of the sleeve 26, and these sleeves 25 and 26 are clamped in position Within the bore 24 by means of the head block 10 which abuts at 32 the end surface of theY The sleeve 25 is held against rota-` sleeve 25. tion relative to the cylinder by a pin and slot connection 33 and is threaded at 34for the reception of a suitable tool to facilitate release of the sleeve from the bore. each of these sleeves 25 and 26 has bores 35 andl 36 of different diameters, and recip` rocably mounted in these bores is an automatic distributing valve 37. This valve is of a usual three-spool differential type having a large central spool 38fi-tting the bores 36 in the sleeves and reduced'end spools 39 fitting the bores 35. As is usual in fluid distribution means of the "type disclosed, the valve 37 controls the supply of motive fluid through passages40 and 41 to the opposite.

of fluid from'a central supply chamber 44 to the passages 40 and 41 in awell known manner. The flange 31 on the sleeve 25 is slotted in a suitable-manner to permitfluid iiow to the central supply chamber 44. Piston controlled throwing passages and 46 are provided connecting the bores at the opposite ends of the valve vwith thev cylinder bore, and these passages conduct live motive fluid from the cylinder to the oppositeends of the valve to shift lthelatt'er into its different positions. Vent passages 47 and 48 are provided in the sleeves 25 and 26, respectively, to relieve the pressure at the'endsl of the valve. A.more detailed description of this Huid distribution means is thought .unnecessary since' it is well known in the art and does not per se enter into the invention.

Theimproved lubricating means for the motor includes a groove 50 formedin the rear motor head 7 and this groove cooperates with the wall of the cylinder to form a lubricant reservoir and this reservoir is connected by a restricted passage 51 with the rear end of the cylinder bore 2. A suitable filling plug 52 is provided to enable the lubricant Within` the reservoir to be replenished when necessary. The flowfof lubricant fromthis lreservoir is entirely automaticand is controlled by the fluctuating pressures lwithin the rear end of the cylinder bore. During normal running of the motor a pressure is built up within the reservoir acting on the surface ofthe lubricant and this pressure is substantially constant.V Therefore, as the pressure Within the rear end of the motor cylinder fluctuates there'is an intermittent flowl of lubricant through the passage 51 to the motor cylinder. l

As shown,y

As a result of this invention it will be noted that an improved rock drilling motor of the pressure fluid type is provided having improved automatic distributing valve structure' including valve sleeves and improved means for maintaining the valve sleeves in position. It will further be noted that this valve structure is of exceedinglysimple design, is readily releasable simply by releasing the rear head block of the motor, and is in-A expensive to manufacture. 'It will still further. be noted that associated with the motor cylinder and rear motor head is an improved lubricating meansv for the motor cylinder which is operated automatically by the fluctuating .pressures Within the motor, this lubricating means including-a lubricant reservoir formed by the l'cylinder wall and a groove in the rear motor headencircling the rifle bar'of the rotation mechanism. These and other advantages will, however, be clearly apparent to those skilled in the art.

While I have in this application specifically described one form which the invention may 'assume in practice, it will be understood 5 that this form ofthe sameis shown for purposes of illustration and-that the invention may be modied and embodied in various other forms without departing from its spirit y or the scope of thel appended claims.

What I claim as new and desire to secure byLettersPatent is: p 1. VIna rock drilling motor, a clyinder, a piston reciprocable in said cylinder, and fluid istribution means for effecting reciprocation of said piston-including a projection on said cylinder having a bore, alined valve sleeves arranged in end abuttlng relationship 1n and ibo fitting said bore and cooperating to form a valve chamber, a valve in said chamber, said I sleeves havingV ports therein controlled by said valve, and a head block closing the rear end ofsaid cylinder and engaging the outer sleeve and retaining said sleeves in said bore.

2. In a rockdrilling motor, a cylinder, a piston reciprocable in said cylinder, and fiuid distribution means for effecting reciprocation of said piston includng a projection on said cylinder having a bore, alined valve sleeves arranged in end abutting relationship in and fitting said bore and cooperating to form a valve chamber, a valve in said chamber, said sleeves having ports therein controlled by said valve, means for preventing rotation of said sleeves relative to said cylinder projection, and a head block closing the rear end of said cylinder and engaging the outer sleeve and retaining said sleeves in said bore.

3. vIn a rockdrilling motor'.A a cylinder, a piston reciprocable in said cylinder, and fluid distribution `means for effecting reciprocati on of said piston including a projection on said cylinder having a bore, alined valve sleeves in said bore cooperating to form a valve chamber, avalve in said chamber, said sleeves hav- Cil ing ports therein controlled by said valve and thc outer sleeve abutting against the inner sleeve, and a head member closing the rear end of the cylinder and engaging the outer sleeve for clamping said sleeves, one through the other, Within said bore.

4. In a rock drilling motor, a cylinder, a

` piston reciprocable in said cylinder, and fluid distribution means for effecting reciprocation of said piston including a projection on said cylinder having a bore, alined valve sleeves in said bore cooperating to form a valve chamber, a valve in said chamber, said sleeves having ports therein controlled by said valve and said outer sleeve having an inner flange abutting against said inner sleeve, and a head member closing the rear end of the cylinder and engaging the outer sleeve for clamping said sleeves, one through the other, Within said bore.

5. In a rock drilling motor, a cylinder, a piston reciprocable in said cylinder, and fluid distribution means for effecting reciprocation of said piston including a projection on said cylinder having a bore, alined valve sleeves in said bore, said sleeves having bores of different diameters cooperating to form a valve chamber, a differential valve in said chamber having spools fitting the bores in said sleeves,` said sleeves having ports therein controlled by said valve and the outer sleeve engaging the inner sleeve to hold the latter in said bore, means for preventing ror tation of said sleeves relative to said cylinder projection, and a head block closing the rear end of said cylinder and engaging said outer sleeve for clamping said sleeves, one through the other, in position Within said bore.

6. In a rock drilling motor, a cylinder, a piston reciprocable in said cylinder, and fluid distribution means for effecting reciprocation of said piston includinga projection on said cylinder having a bore, alined valve sleeves arranged in end abutting relationship in and fitting said bore, each of' said sleeves having a large bore and a reduced bore and said bores cooperating to form a valve charnber, a differential valve in said chamber having` an enlarged flange fitting said large bores in said sleeves and reduced flanges fitting said reduced bores, said sleeves having ports therein controlled by said valve, and a head block closing the rear end of said cylinder and engaging the outer sleeve to clamp said sleeves in said bore.

7. In a rock drilling motor, a cylinder, a piston reciprocable in said cylinder, and fluid distribution means for effecting reciprocation of said piston including a projection on said cylinder having a bore, alined valve sleeves arranged in end abutting relationship in and fitting said bore. each of said sleeves having a large bore and a reduced bore and said bores cooperating to form a valve cham- 

